Method and apparatus for feeding parallel wire strands

ABSTRACT

Method and apparatus for feeding or delivering a group of parallel wire strands under controlled tension wherein a feed spool on which the strands are spirally coiled in layers separated by an interwound metal band is indirectly driven by rewinding the metal band on a second takeup spool having variable-speed drive means, and the rate of feed of the wire strands being unwound from the feed spool is regulated by sensing the position of a freely hanging or slack portion of the strands between the feed spool and a braking device which subsequently provides a controlled tension on the strands for further processing.

United States Patent Inventors Appl. No. Filed Patented Assignee Priority METHOD AND APPARATUS FOR FEEDING PARALLEL WIRE STRANDS 11 Claims, 2 Drawing Figs.

US. Cl 242/54, 242/55, 242/67.3, 242/75.3

Int. Cl B6511 75/00 Field of Search... 242/54, 55,

Primary Examiner-Stanley N. Gilreath Assistant ExaminerWerner H. Schroeder Attorney-Johnston, Root, OKeeffe, Keil, Thompson &

Shunleff ABSTRACT: Method and apparatus for feeding or delivering a group of parallel wire strands under controlled tension wherein a feed spool on which the strands are spirally coiled in layers separated by an interwound metal band is indirectly driven by rewinding the metal band on a second takeup spool having variable-speed drive means, and the rate of feed of the wire strands being unwound from the feed spool is regulated by sensing the position of a freely hanging or slack portion of the strands between the feed spool and a braking device which subsequently provides a controlled tension on the strands for further processing.

III/I I III INVENTORS: KURT-JURGEN SCHULZE HElNRlCH GIESEN WILHELM HAAS KURT HEUER @WW 'wfiwa aw ATTYS PATENTEU JUN 8 l97l FIG. 2

SHEET 2 OF 2 llllll l INVENTORS: KURT-JURGEN SCHULZE HEINRICH GIESEN WILHELNI HAAS KURT HEUER ATT'YS METHOD AND APPARATUS FOR FEEDING PARALLEL WIRE STRANDS The invention generally relates to a method and to an apparatus for feeding a plurality of wire strands initially wound on a bobbin, spool or so-called warp beam, said strands consisting of individual wires, twisted strands or wire cables which lie parallel and closely adjacent to one another, the individual coiled layers of parallel adjacent strands being separated from one another by a thin metal band which has been interwound with the strands on the feed spool. The strands are fed to a device for their processing, especially conventional apparatus for making tire inlays.

For the production of reinforcing inlays for vehicle tires or conveyor belts, it is conventional to employ a group of wires, wire strands or wire cables which are coated both above and below with a rubber layer. Such inlays require about 300 to 500 or even more substantially parallel wires, wire strands or wire cables arranged next to one another at the spacing prescribed for the finished inlay product, and this large number of wires, strands or cables are fed to the processing device under a preferably controlled tension.

The wires, wire strands or wire cables, designated hereinafter as wire strands" have generally been wound individually on reels. A runoff gate known from the textile industry, which accommodated about 300 to 500 reels, then delivered the strands from each individual reel to the processing apparatus for making the inlays. This runoff gate demands a considerable amount of space. The insertion of the full spools or reels and the removal of the empty spools is complicated and quite time consuming. When one of the 300 to 500 spools of the supply of a wire strand is depleted, then the processing operation has to be interrupted and the residual strands still present on the remaining spools can no longer be used as a feed. For embedding of the group of strands as an inlay or tire cord in a layer of rubber, it is requisite that in each individual element or strand of the cord group there prevail the same tensile stress. This tensile stress or tension on the strands must be maintained constant during the processing into an inlay structure by means of a suitable braking mechanism. The level of the tensile stress or force depends on the type of product produced but generally falls in the range of from to 2 kilograms (force), and in some cases even higher.

Aside from other disadvantages, it has been established that the use of the above mentioned individual spools and runoff gate fails to maintain or constantly control the tensile stress in the individual elements or strands of the cord group'being processed. It has already been proposed to employ a single feed spool for the conveyance or delivery of the group of strands, wherein the wound or coiled group of parallel and closely adjacent strands are separated in layers from one another by an inserted or interwound metal band. The structure and assembly of this single feed spool is fully disclosed in the copending and commonly assigned application of Heuer et al., Ser. No. 703,154, filed Feb. 5, 1968, the subject matter of which is included herein by reference as fully as if set forth in its entirety.

Utilizing this single feed spool the present invention is directed to the problem of designing a method and means for feeding the wire strand group to the processing machine in such a way that the cord group is introduced virtually without tension into the braking device positioned before the inlay processing apparatus. At this initial feed point the unwinding must take place in such a way that it can adapt itself to every variation or fluctuation as the strands pass to and through the inlay processing machine. Furthermore, it is desirable to reuse the metal band separating the individual strand layers in the feed spool after the strands have been completely used. Other objects and advantages of the invention will be more apparent from the following detailed disclosure.

it has now been found, in accordance with one aspect of the invention, that one can achieve considerably improved results in providing a feed supply of substantially parallel, closely adjacent wire strands as they are drawn by any conventional means into a subsequent processing step provided that one employs the above noted single feed spool wound in alternate layers with the parallel strands and metal band. The method of the invention then essentially includes the steps of unwinding the plurality of wire strands to form a planar group by indirect drive over the simultaneously unwinding metal band, and then supplying the planar group of wire strands over a free space, in which the tension of the strands results essentially from their own weight, to a braking interval wherein a controlled tension can be imparted to the strands for further processing.

In carrying out this feed method, it is preferable to unwind the protective or separating metal band from the lower portion of the normally freely rotating feed spool in one direction while withdrawing the planar group of wire strands from the top portion of the spool in the opposite or feed direction, the metal band being recovered by rewinding it on a positively driven and initially empty takeup spool. in order to be certain that there is little or no tension on the wire strands as they are initially fed into the braking interval, it is especially desirable to permit the group of wire strands to sag or form a downwardly projecting shallow are or loop in the free space between their liftoff line on the feed spool and the point at which they are received in the braking interval. Furthermore, it is then possible to control the speed of the unwinding metal band in response to the position of the group of wire strands as they sag downwardly in the free space.

This method according to the invention assures, at drawoff speeds up to 25 m./min. and sometimes even more, a uniform, trouble-free parallel running of the wire strands, while the tensile stress in the individual elements or strands of the entire group is equal and constant throughout its subsequent processing. By avoiding any substantial tension on the strands, other than that contributed by their own weight in the interval between the feed spool and suitable braking means, slight dif ferences in the rate of speed supply cannot be transmitted to the action of the braking means and the differences which might occur can be rapidly corrected by appropriate response to the exact position of the strands in the sagging feed path.

Since the load of the group of wire strands sagging between the liftoff line on the feed spool and the braking device arises only through its own weight, it is possible by means of the braking interval or braking stage to generate a uniform tension on the individual wires. By "liftoff line" there is meant in this context the line running transversely on the cylindrical surface of the loaded feed spool parallel to the spool axis, i.e. the line at which the group of strands is lifted off from the surface of the winding on the feed spool. ln the remainder of this text, the term spool" is used in preference to such terms as reel or warp beam, all of which fall within the generic expression winding member".

The control of the metal band speed is accomplished in a preferred manner by continuously sensing the position of the are or loop formed by the hanging group of wire strands in the free space between the liftoff line and the braking stage or interval. The length variations of the hanging are or loop are then utilized by means of conventional mechanical or electromechanical devices which convert the position of a sensing member into a variation of the band winding speed, thereby accommodating the speed of the indirect drive to the conditions prevailing in the subsequent processing stage.

The tensile stress or tension to be adjusted or maintained in the wire strands, preferably in the range of 0 to 2 kilograms as predetermined by the subsequent processing apparatus, is generated by means of a braking stage or interval in which the strands can be braked in a conventional manner. During the unwinding of the metal band, the turning rate or rotational velocity of the feed spool containing the wire strands must be increased in direct proportion to its decreasing radius. So that the rate of increase in this rotational velocity of the feed spool occurs continuously rather than in discrete jumps, the runoff of the wire strands is preferably damped by a braking force counteracting the unwinding pull of the metal band, i.e. by applying a braking pressure to the shaft or flanges of the spool itself.

A further object of the invention is to provide suitable apparatus in a combination which is especially adapted to carry out the method of feeding the parallel wire strands under controlled tension into any typical processing apparatus which requires a so-called warp of individual wires, strands or cords, e.g. in making tire cords or reinforcing inlays for conveyor belts or the like. Such processing apparatus does not constitute a specific feature of the present invention, and it will be understood that it merely follows the usual braking means adapted to place a braking tension on the wire strands, such braking means essentially representing the initial step or stage of this processing apparatus. Instead, the present invention is directly concerned with the combination of particular means for initially supplying the wire strands from a unitary feed spool to the braking means of the subsequent processing apparatus.

Viewed in this manner, the apparatus of the present invention includes a pair of flanged spools supported rotatably about horizontal parallel axes, one of the spools serving as the feed spool as defined above with a continuous metal band coiled and interposed between individual coiled layers of substantially parallel and closely adjacent wire strands. The other spool serves as a take up means for rewinding the metal band from the feed spool while providing an indirect drive of the feed spool over this metal band. Thus, drive means with controllable speed, e.g. a variable speed motor, are provided to positively rotate the takeup spool with the metal band being wound thereon operating to indirectly drive the feed spool.

The two spools when empty preferably have the same structure, i.e. the same dimensions in terms of flange radius and spindle or axle length between opposing end flanges, so that they can be interchangeably used as either feed spools or takeup spools. Their axes of rotation preferably fall in the same horizontal plane so that each spool can be connected to a common baseplate through supporting trestles. More importantly, it is desirable to position the takeup spool as the first spool in the feed direction of the wire strands while the feed spool is positioned as the second spool in this same feed direction. The metal band is then unwound in a direction opposite that of the strand feed, preferably from the lower portion of the feed spool while the strands are lifted off the top portion of the feed spool, eg at a lift off position of anywhere from about 5 to 100, preferably to 90, from a vertical plane through the axis of the feed spool in the direction of the spool rotation.

Braking means, which can include conventional elements, are employed to provide a controlled tension on the plurality of wire strands as they are drawn into further processing steps, it being necessary however to arrange such braking means at a spaced distance from the second or feed spool in the feed direction so that the wire strands as a planar group will hang freely in this initial feed path between the feed spool and the braking means. The strands are drawn through the braking means or so-called braking interval by any conventional drawing or transporting apparatus, e.g. nip rolls or the like, and by applying a frictional pressure on the strands in the braking interval, the tension of the strands can be accurately controlled even at relatively high drawing or transporting speeds. The braking means preferably includes a conventional comb to receive and guide the strands as they are received from the feed spool, a flat magnetic plate which accurately positions and supports the strands adjacent the comb, and a plurality of rollers or similar friction bearing members which contact the running wire strands so as to exert a braking tension thereon. By suitably loading one or more of these rollers with weights, preferably so that the load can be adjusted, the amount of tension can be easily regulated and maintained at a constant or substantially uniform value, provided that there is no interference from the initial feed spool as it supplies the strands without any substantial tension.

The control of the feed spool turning rate is achieved in a highly satisfactory manner by a sensing member arranged in riding contact with the freely hanging feed path of the wire strands between the feed spool and the braking means. This sensing member, e.g. in the form of a light roller or dancer arm, is preferably positioned at or near the lowest point of the freely hanging feed path and is pivoted or otherwise mounted to move freely along with the changing vertical position of the hanging feed path. Means can then be provided which are responsive to the movement of this sensing member to vary the speed of the drive means.

The apparatus of the invention is described in greater detail in connection with one preferred embodiment as shown in the accompanying drawing wherein:

FIG. I is a partially schematic side elevational view of the apparatus; and

FIG. 2 is a top plan view of the same apparatus.

As shown in the drawings, the apparatus essentially includes the fully wound feed spool l and the empty takeup spool 2, which winds up the metal band 3. The entire planar group of wire strands 4 runs off from the feed spool 11, then forms a hanging loop, on which there rests the dancer roller arm 5, and then passes over a fixed arcuate guide strip 6 into the comb 7 of the braking stage. The wire strands 4 run with equal and uniform spacing from the comb 7 over the flat magnetic plate 8, which is secured onto the frame 9. At the opposite end of the magnetic plate 8, there are arranged rollers ll, 12, 13, which are rotatably supported in the frame 14. The roller 13 further carries on its shaft 15 a brakedrum 16, about which there is applied a band I7 provided with a brake lining. This band is connected to a lever arm 18 which carries a slidable weight 19 so as to adjust the braking effect on this roller. The brakeheads 20 rest on rollers ll, 12 so that the braking pressure on the wire strands can be adjusted by means of the weights 2] slidable on the lever arms 10.

Feed spool 1 and the initially empty takeup spool 2 have identical spool bodies 22, i.e. an identical spindle and flange construction, with oppositely disposed flanges 22 which are rigidly connected with the axle 23. The axle of each spool is carried in the bearings 25 securely attached to the supporting trestle 24. On the axle 23 there is mounted at one lateral end 26 a drum or belt pulley 27. The supporting trestles 24 include skids 28, which can slide into the mounting guides 30 attached to the baseplate 29 up to the adjustable stop 31 (Fig. 2). The spool flanges 22, the spindle, or axle 23, the bearings 25, the skids 28 and the supporting trestle 24 form a single unit which can be wound, transported and unwound in this unitary form, i.e. without removing the individual spools. The drum or belt pulley 27 of the unit containing the takeup spool 2 is connected for rotation by the drive belt 32 with the driving wheel or pulley 33 on the drive shaft of the variable speed motor 34 having conventional speed control means 34a. On the drum or belt pulley 27 of the unit containing the feed spool 11, there rests a brake jaw 35 having a horizontally extending arm 36 which carries a movably positioned weight 37, the brake jaw being pivoted about a pin or stud 38 of the carrier frame 24 (Fig. 1). The two units are attached by the straps or clamps 39 to the baseplate 29. FIG. I further indicates the swinging range of the dancer roller arm 5, a lower position of the wire strand feed path 4a near the end of the feed supply being shown in broken lines.

In the unwinding and winding of the metal band 3, damage occurs if the metal band edges rub on the flanges 22 of the two spools. Such damage, which prevents a reuse of the metal band, is avoided according to the invention if the spools rotatably mounted in the supporting trestles stand opposite one another in such a way that the axial displacement between two spools is smaller than the difference between the metal band width and the clear space of the flanges of the spools. In other words, the two spools should have parallel spindles or axes and the distance between these axes should be sufficiently close to permit the flanges on the spools to act as guides for the metal band as it passes from one spool to the other. In most cases, this distance between the axes will be less than two flange diameters.

The braking stage for generating a drawing tension on the strands preferably contains a comb 7 which sets the same spacing between the individual strands of the group of strands, e.g. as required for a tire cord. In the preferred embodiment shown in the drawings, the braking stage also includes a flat magnetic plate 8 and a roller trio ill, l2, 13 in which system one or more of these rollers are equipped with brake drums, preferably the large roller 13 having brakedrum l6 partially encircled by a frictionally engaged band 17 connected to lever arm 18 carrying a slidable weight 19.

It is particularly advantageous according to the invention if each spool is rigidly connected with the axle or spindle turnably carried in the supporting trestle, in such a manner that the spool, axle, trestle and the associated brakedrum or belt pulley form a single movable or replaceable unit. The supporting trestle 24 is provided with skids 28 which are slidable in guide rails 30 on the baseplate 29 up to an adjustable stop. It is thereby possible to easily and rapidly attach and release the entire spool and trestle unit on the baseplate. In the case of larger and heavier units, the skids can be constructed in such a way that the spool and trestle units may be conveyed with fork lifts.

The force needed for damping the rotary movement of the feed spool containing the layers of strands interwound with the metal band is preferably generated with the swingable brake jaw 35 pivoted on the supporting trestle although other suitable braking means can also be employed. The brake jaw is thus connected with the spool and trestle unit fastened to the baseplate and is applied against the cylindrical surface of the drum or belt pulley 27. Through the sliding of the weight 37 on the lever arm 36, the required braking force can be adapted to the drawoff movement. The takeup spool can include this same brake jaw which is merely swung out of operation so that the drum or pulley 27 can be engaged by the belt 32.

In order to reduce the spatial dimensions of the apparatus, the drive with controllable speed is preferably arranged between the supporting trestles of the two spools. The motor or drive means having a controllable speed is thus easily connected by means of a drive belt with the drum or the belt pulley of the takeup spool.

As the metal band 3 is wound onto the takeup spool 2, the wire strands 4 are continuously fed in their sagging path while in contact with the dancer arm 5 which acts as a sensing member to monitor this loop or arcuate path through the entire operation. Thus, as the feed supply of strands is depleted as the feed spool is unwound, the dancer arm 5 drops downwardly with the downward movement of the feed path, and this mechanical movement is relayed to the drive means 34 through a conventional speed control unit 34a so as to gradually increase the speed of rotation of the feed spool as it is indirectly driven over the metal band. This variable speed control also serves to avoid any large fluctuations in the position of the wire strands 4 as they pass through the free space between the feed spool 1 and the guide strip 6 at the beginning of the braking interval. in this manner, the initial supply of strands as they leave the feed roll are kept substantially free of tension so that they do not interfere with the uniform braking tension which must be subsequently applied. Likewise, disturbances in subsequent processing steps do not affect the uniform rate of feed from the feed spool.

After the conclusion of the unwinding process, the empty feed spool on the baseplate is simply exchanged with the takeup spool which then contains the metal band. This spool wound with the metal band is used in a separate winding device for the production of a new feed spool.

Any number of minor variations can be made in the specific embodiment of the invention illustrated herein without departing from the spirit or scope of the invention.

We claim:

ll. A method of feeding a plurality of wire strands under controlled tension, said strands lying parallel and closely adjacent one another while wound in layers around a feed spool with the individual layers being separated from each other by a metal band interwound therebetween, said method comprising: unwinding said metal band to rotatably drive said feed spool, thereby unwinding said plurality of wire strands to form a planar group thereof which is lifted off said feed spool; supplying the planar group of wire strands over a free space, in which the tension of the strands results essentially from their own weight, to a braking interval wherein a controlled tension is commonly imparted to said strands for further processing, said group of wire strands sagging downwardly in the free space between the liftoff line on said feed spool and the braking interval; and controlling the speed of the unwinding metal band in response to the position of the group of wire strands sagging in said free space.

2. A method as claimed in claim 1 wherein the force of tension imparted to each of said strands in said braking interval amounts to not more than about 2 kilograms.

3. A method as claimed in claim 1 wherein the unwinding and runoff of the wire strands is damped by applying a braking pressure which to said feed spool counteracts the unwinding pull of the metal band;

4. Apparatus for feeding a plurality of wire strands under controlled tension, said strands lying parallel and closely adjacent one another while wound in layers around a feed spool with the individual layers being separated from each other by a metal band interwound therebetween, said apparatus comprising:

a pair of flanged spools supported rotatably about horizontal parallel axes, the first of said spools viewed in the feed direction of the wire strands being arranged to take up the metal band fromthe second of said spools which acts as the feed spool;

drive means with controllable speed to positively rotate said first spool with the metal band being wound thereon operating to indirectly drive said second spool;

braking means to apply a tension on said plurality of wire strands as they are drawn into further processing, said braking means being arranged at a spaced distance from said second spool in the feed direction such that the wire strands hang freely in a feed path between said second spool and said braking means;

a sensing member arranged in riding contact with the freely hanging feed path of said wire strands; and

means responsive to the movement of said sensing member to vary the speed of said drive means.

5. Apparatus as claimed in claim 4 wherein the axial displacement between the two spools is smaller than the difference between the width of the metal band and the clear width of the spool flanges.

6. Apparatus as claimed in claim 4 wherein said braking means for the wire strands includes a comb to receive and guide the strands from said feed spool, a flat magnetic plate supporting the strands adjacent said comb, and a plurality of rollers adapted to exert a braking tension on said strands.

7. Apparatus as claimed in claim 6 wherein at least three rollers are in tangential contact above and below said wire strands with at least one of said rollers bearing a brakedrum partially encircled by a frictionally engaged band which is connected to a lever arm having a weight slidable thereon to control the load placed on said brakedrum by said frictionally engaged band.

8. Apparatus as claimed in claim 4 wherein each spool is rigidly connected to its axle which carries a brakedrum projecting axially outwardly from the flange at one end of the spool, said axle being turnably supported in a trestle-support ing means, and a frictional braking member mounted on said trestle-supporting means to frictionally engage said brakedrum on its cylindrical surface with means to vary the resulting frictional load.

9. Apparatus as claimed in claim 8 wherein said spool, axle, brakedrum, supporting trestle and frictional braking member constitute a single movable unit for each of the two spools, and each unit is positioned on a baseplate having means to releasably fasten the units in place.

10. Apparatus as claimed in claim 3 wherein said drive spool byadrive belt engaging the projecting drum. means with controllable speed is positioned between the unit 11. A method as claimed in claim ll wherein the unwinding carrying the feed spool and the unit carrying the takeup spool, metal band is collected on a positively driven takeup spool at a and said drive means is operably connected to said takeup controlled speed. 

1. A method of feeding a plurality of wire strands under controlled tension, said strands lying parallel and closely adjacent one another while wound in layers around a feed spool with the individual layers being separated from each other by a metal band interwound therebetween, said method comprising: unwinding said metal band to rotatably drive said feed spool, thereby unwinding said plurality of wire strands to form a planar group thereof which is lifted off said feed spool; supplying the planar group of wire strands over a free space, in which the tension of the strands results essentially from their own weight, to a braking interval wherein a controlled tension is commonly imparted to said strands for further processing, said group of wire strands sagging downwardly in the free space between the liftoff line on said feed spool and the braking interval; and controlling the speed of the unwinding metal band in response to the position of the group of wire strands sagging in said free space.
 2. A method as claimed in claim 1 wherein the force of tension imparted to each of said strands in said braking interval amounts to not more than about 2 kilograms.
 3. A method as claimed in claim 1 wherein the unwinding and runoff of the wire strands is damped by applying a braking pressure which to said feed spool counteracts the unwinding pull of the metal band.
 4. Apparatus for feeding a plurality of wire strands under controlled tension, said strands lying parallel and closely adjacent one another while wound in layers around a feed spool with the individual layers being separated from each other by a metal band interwound therebetween, said apparatus comprising: a pair of flanged spools supported rotatably about horizontal parallel axes, the first of said spools viewed in the feed direction of the wire strands being arranged to take up the metal band from the second of said spools which acts as the feed spool; drive means with controllable speed to positively rotate said first spool with the metal band being wound thereon operating to indirectly drive said second spool; braking means to apply a tension on said plurality of wire strands as they are drawn into further processing, said braking means being arranged at a spaced distance from said second spool in the feed direction such that the wire strands hang freely in a feed path between said second spool and said braking means; a sensing member arranged in riding contact with the freely hanging feed path of said wire strands; and means responsive to the movement of said sensing member to vary the speed of said drive means.
 5. Apparatus as claimed in claim 4 wherein the axial displacement between the two spools is smaller than the difference between the width of the metal band and the clear width of the spool flanges.
 6. Apparatus as claimed in claim 4 wherein said braking means for the wire strands includes a comb to receive and guide the strands from said feed spool, a flat magnetic plate supporting the strands adjacent said comb, and a plurality of rollers adapted to exert a braking tension on said strands.
 7. Apparatus as claimed in claim 6 wherein at least three rollers are in tangential contact above and below said wire strands with at least one of said rollers bearing a brakedrum partially encircled by a frictionally engaged band which is connected to a lever arm having a weight slidable thereon to control the load placed on said brakedrum by said frictionally engaged band.
 8. Apparatus as claimed in claim 4 wherein each spool is rigidly connected to its axle which carries a brakedrum projecting axially outwardly from the flange at one end of the spool, said axle being turnably supported in a trestle-supporting means, and a frictional braking member mounted on said trestle-supporting means to frictionally engage said brakedrum on its cylindrical surface with means to vary the resulting frictional load.
 9. Apparatus as claimed in claim 8 wherein said spool, axle, brakedrum, supporting trestle and frictional braking member constitute a single movable unit for each of the two spools, and each unit is positioned on a baseplate having means to releasably fasten the units in place.
 10. Apparatus as claimed in claim 8 wherein said drive means with controllable speed is positioned between the unit carrying the feed spool and the unit carrying the takeup spool, and said drive means is operably connected to said takeup spool by a drive belt engaging the projecting drum.
 11. A method as claimed in claim 1 wherein the unwinding metal band is collected on a positively driven takeup spool at a controlled speed. 